Earth from space/thecontaminated.com

Men in traditional dress light candles, Jakarta, Indonesia, Earth Hour, March 28, 2009/Dadang Tri, Reuters, The Vancouver Sun, vancouversun.com

Tonight, Saturday night, March 26, 2011, from 8:30 to 9:30 p.m. local time, people, groups, businesses and governments all over the world will be switching off lights large and small for 60 minutes in observation of Earth Hour.

Brooklyn Bridge goes dark during Earth Hour, March 28, 2009/Don Emmert, AFP-Getty Images, The Vancouver Sun, vancouversun.com

This year’s rolling, globe-spanning Brown Out will be the fifth since Australia’s World Wildlife Fund, Leo Burnett agency and Fairfax Media joined forces to organize the first event in Sydney, Australia on March 31, 2007.

Sydney Harbor goes semi-dark for Earth Hour, March 31, 2007/vankatwijk, flickr.com

It has grown into quite a happening in the years since. Lots of celebrating. Lots of candle-lighting. Lots of people gathering to watch and take pictures as iconic buildings, monuments and cityscapes go temporarily dark.

Fire acrobats perform in Sofia, Bulgaria, Earth Hour, March 28, 2009/Stoyan Nenov, Reuters, The Vancouver Sun, vancouversun.com

Students light candles in Peace Memorial Park, Hiroshima, Japan, Earth Hour, March 27, 2010/Junko Kimura, Getty, The Vancouver Sun, vancouversun.com

Friends take a group shot as Eiffel Tower goes dark for Earth Hour, image from Earth Hour 2011 Official Video/earthhour.org, youtube.com

Call it silly. Critics do. Earth Hour doesn’t solve or help anything, they say. It just gives people an easy way to feel they’ve done something good for the planet when they really haven’t done anything at all.

Woman with candle during Earth Hour, image from Earth Hour 2011 Official Video/earthhour.org, youtube.com

Others disagree. “Earth Hour has a unique ability to unite and empower people around the world,” Richard Dixon, director of WWF Scotland, told the BBC. (Scotland is all in this year.) It lets people have fun organizing their own events, he said, while still sending “an incredibly powerful global message to world leaders of the concern we all share about climate change.”

Earth from space/NASA

Whatever your opinion and whether you plan to participate or not — 8:30 to 9:30 p.m tonight local time if you do — you have to admit that watching the lights on huge monuments go off for an hour and then back on again must be fun.  And the photos people have taken of these happenings are cool, too.

Brandenburg Gate, Berlin, Germany, Earth Hour, March 27, 2010/Reuters, The Telegraph, telegraph.com

Big Ben, House of Parliament, London, England, Earth Hour, March 28, 2009/Leon Neal, AFP-Getty, The Vancouver Sun, vancouversun.com

Burj al Arab Hotel, Dubai, Earth Hour, March 28, 2009/Fouad Juez, Reuters, The Vancouver Sun, vancouversun.com

You can see more photo galleries here, here, here and here, and you can watch the Official Earth Hour 2011 Video with fun footage of iconic structures going dark by clicking the image below:

St. Louis Arch, Earth Hour, March 27, 2010, image from "Earth Hour 2011 Official Video"/Earthhour.org, youtube.com

But the coolest photo gallery of all is an interactive display called “Before and During Pictures of Earth Hour 2010” created by Denny Tang that lets you scroll through images of 24 sites and turn the lights off and on — and off and on again as often as you like — just by moving your cursor. Click here or any of the next three images to try it.  It’s fun!

Sphinx and Pyramids, Giza, Egypt, Earth Hour, March 27, 010/Jason Larkin, photoshoptutorials.ws

National Stadium, Beijing, China, Earth Hour, March 27, 2010/Janek Zdzrski, WWF, photoshoptutorials.ws

Luna Park, Sydney, Australia, Earth Hour, March 27, 2010/Getty, photoshoptutorials.ws

Remember, if you do want to take part in Earth Hour 2011, just switch off your lights tonight from 8:30 to 9:30 p.m. Then see if your neighborhood looks different with fewer lights burning less energy — and if maybe you can glimpse a few more stars.

Empire State Building goes dark for Earth Hour, March 27, 2010/Reuters, The Telegraph, telegraph.com

Learn more:

• The World Wildlife Fund (WFF) and Leo Burnett Agency get most of the credit or blame for launching Earth Hour. Learn more about these organizations and the history of Earth Hour here and here.

• Visit the Earth Hour website here.

• Read two good articles about Earth Hour in The Vancouver Sun here and here.